1. Field of the Invention
This invention relates to a screen for a projector, more particularly to a screen with a concave reflection surface which can provide increased gain and horizontal viewing cone for a viewer and which can decrease the reflected light emitted from light sources other than the projector.
2. Description of the Related Art
The improvement of this invention is directed to a conventional screen which is used for a projector.
Generally speaking, there are two principal types of conventional screens which are used for projectors. The first type of screen, such as a white linen has a wider viewing cone for a viewer, but its gain of screen is poor so that the images that fall on the screen can be clearly visible only under dim light conditions. The second type of screen, such as a metal which is coated with a piece of film, has a better gain of screen for the viewer, but its viewing cone is narrower than that of the first type so that the viewer can watch clearly the images on the screen only within a limited scope.
Because the conventional screen has an even reflection surface, light that is emitted from the projector is reflected from the even reflection surface of the screen only in a regular direction. The gain of the screen is in inverse proportion to the viewing cone of the screen. Accordingly, the gain and the viewing cone of the screen can not be increased simultaneously so that the practicability of the conventional screen is limited.